Headphones and headsets in which the hoop band contact pressure force is adjustable have long been known. Hereinafter the term hoop band contact pressure force is used to denote that force with which the ear pads are pressed against the head when the headphones or headset is fitted. In typical configurations that force can be adjusted by the provision of a possible way of altering the geometry of the hoop band or the coupling between the hoop band and the ear pads.
U.S. Pat. No. 5,293,647 describes headphones in which a one-part head hoop band is coupled at both ends to a respective ear pad by way of two interconnected rotary joints. The connected rotary joints are respectively fixed by way of a common fixing plate which can be operated by way of a centrally mounted adjusting button with a traction spring. When the fixing plate is released for unlocking the rotary joints by way of the central adjusting button the position of the ear pads relative to the head hoop band can be altered. The described headphones thus permit a certain adjustability of the hoop band contact pressure force but it will be noted that they do not permit comfortable operation as a total of four rotary joints are to be adjusted jointly in regard to an overall effect.
U.S. Pat. No. 3,682,268 describes headphones having a head hoop band comprising a plurality of connected parts which are substantially in the form of hollow bodies. One or more springs integrated into the head hoop band produce a hoop band contact pressure force for pressing the ear pads against the head when the headphones are fitted. It will be noted however that the stress of the springs and therewith the hoop band contact pressure force cannot be varied in those headphones. In addition the described structure of the head hoop band in the form of hollow bodies results in markedly larger structural shapes than can be achieved with present day head hoop band forms.